Tool



Dec. 11, 1945.

H. A. BOTHNER Filed Nov. 11, 1944 IN VEN TOR.

Patented Den. 11, 1945 UNITED STATES PATENT OFFICE TOOL Herman A. Bothner, Springfield, Mass.

Application November 11, 1944, Serial N0. 562,941

1 Claim.

'Ihis invention relates to improvements in tools and is directea more particularly to improvements in tools for 1&pping holes, apertures, and the 1ike.

The principal objects of the invention are directea to the provision of a lapping too1 having an expansible 1ap member and provided with novel means for expanding the same.

It is customary in lapping tools to provide means for expanding the same for varying the size thereof but have been objectionable since the means for expanding the 1ap has resulted in the 1ap having a neu-uniform diameter.

In accordance With this invention the lapping tool is provided which 'is characterized by an expansible lap member and. means for expanding the same to maintain a uniform diameter throughout its length.

With the foregoing and various other nove1 features and advantages and other objects 01 my invention as will become more apparent as the description proceeds, the invention consists in certain novel features of construction and in the combination and arrangement of parts as will be hereinafter more particularly pointed out in the c1aim hereunto annexed and more 11111y described and referred to in connection with the accompanying drawing wherein:

Fig. 1 is a side elevational view of a. lapping too1 embodying the features cf the invention; and

Figs. 2 and 3 are sectional p1an views on the 1ines 2-2 and 3-3 of Fig. 1.

Referring now to the drawing more in detail, the invention will be fu1ly described.

The main body of the tool of the invention inc1udes a shank portion 2, an intermediate threaded portion 4 and a tapering portion 8.

The shank portion is adapted for engagement by a chuck or other suitable means and, 01 course may be manipulated in any desired manner. A nut 8 is provided with an internally threaded socket for engagement with the threaded Dortion 4.

A lapping element in the form o1 a sleeve I is provided which has a flange I2 on its one end. Said member I0 is split at 14 longitudinally so as to De expansible. The element is also'provided with a longitudinal bore which is complemental to the tapering member 6.

The taper of the part 6 and bore of the member I0 may be as desired so that the member 10 may be expanded by the part 6.

The nut 8 is provided with a socket, for receiving the flange I2 0f the member I0 and it has a s1ot to facilitate the insertion of the flange I2 in the socket, see Fig. 2.

The parts may be relatively proportioned as may be desired and. the part I0 may be so made and adapted so as to be chargeable with some abrasive material which is for the lapping operation to be performed.

In Fig. 1 the parts are shown in their assemb1ed reiation and as the part 4 is screwed into the nut 8 the tapering member 6 causes the lap I0 to expand to the desired degree and, as stated,

the member 6 may have any taper desired.

It will be observed that the tool is of such a construction that the 1ap 10 may be readily and ea.siiy expanded to within very narrow 1imits all to the end that acci1racy may be obtained whil e at the same time the lap has a. uniform diameter at all times.

When it is desired to disassemble the too1 the pa.rt 4 is screwed out oi the nut 8 so that the main body may be withdrawn axially through the nut whereby the tapering part is withdrawn from the bore of the 1ap and then the inner end of the lap member is removed from the nut 8.

The invention may be embodied in other specific forms without departing from the essential characteristics thereof. Hence, the present embodiments are therefore to be considered in all respects merely as being illustrative and not as being restrictive, the scope 015 the invention beim indicated by the appended claim rather than by the Ioregoing description, and all modifications and variations as fall within the meaning and purview and range of equivalency of the appended c1aim am therefore intended to be embraced therein.

What it is desired to c1aim and secure by Letters Patent of the United States is:

A too1 of the dass described comprising in combination, an elongated body member having upper manually engageable and lower downwardly tapering portions with a screw threaded portion therebetween, a nut separable from said body having a. longitudinal bore screw threaded at its upper end for engaging said screw threaded portion and the lower end thereof having an opening extending outwardly from said bore through a. side thereof providing sockets for receiving the upper flange and. adjacent Portion of a lap member a one-piano lap member having a flange at its upper end and provided with a longitudinal bore conforming to the lower tapering portion of the body and with a. longitudinally extending s1ot at a. side thereofleading into said bore, all adapted and. arranged whereby with said nut separated irom said body the flange and adjacent portion of the 1ap member may be inserted in the sockets of the nut and the lower tapering portion o: the body may be passed through the bore of the nut into the bore oi the 1ap to engage the screw threads of the body and nut so that an rotation 01 the nut relative to the body the lower tapering end of the body acts in the bore of the 1ap to expand it.

HERMAN A. BOIHNER. 

